Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 12 Jan 2015

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

10(6)

21(21)

14(-)

23(10)

0.4(4)

10(43)

South

7(4)

23(23)

5(-)

22(10)

0.4(4)

11(44)

East

5(3)

21(21)

6(-)

38(16)

0.2(2)

12(51)

West

5(3)

24(24)

19(-)

37(16)

0.4(4)

11(44)

Central

8(5)

20(20)

49(-)

39(16)

0.3(3)

8(35)

1-hr PM2.5 (µg/m3)b Readings on 12 Jan 2015

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

11

8

7

11

14

9

7

7

13

17

13

13

South

7

5

10

5

4

6

8

7

8

13

20

23

East

7

10

10

11

9

11

10

11

12

14

19

14

West

10

6

7

11

9

8

7

9

10

14

16

15

Central

7

8

6

8

5

3

7

6

9

12

11

16

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

11

13

8

10

9

11

4

7

7

13

11

-

South

23

19

17

18

9

13

4

9

8

6

3

-

East

12

11

16

13

10

19

8

18

11

12

10

-

West

20

13

10

13

8

7

6

6

7

15

18

-

Central

10

10

10

10

9

11

4

14

10

10

3

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
12 Jan 2015

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

38

36

32

33

35

34

33

32

37

46

53

55

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

55

54

53

52

47

47

37

39

34

42

39

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.